Knife mounting



Dec. 21, 1943.

P. N. OTTERSLAND KNIFE MOUNTING Filed June 28, 1941 INVENTOR P5752 /V.OTTFRSLAND A'ITORN s III III-ll.

Patented Dec. 21, 1943 UNITED' STATES PATENT OFFICE KNIFE MOUNTING PeterN. Ottersland, Watertown, N. Y. Application June 28, 1941, Serial No.400,223

5 Claims.

This invention relates to 'a knife mounting, and more particularly to aknife mounting for,

chippers.

Chippers such as those used for chipping or cutting logs into chipssuitable for use in paper pulp machines usually comprise a cutting disk.and a plurality of chipper knives mounted thereon. These disks rotate athigh speed and the knives are subjected to very heavy strains and wearand must be rigidly mounted. Moreover, the knives should be soconstructed and mounted that after they have been re-ground andsharpened the effective width can be maintained by compensating for theamount ground off.

This invention has for its salient object to provide a knife structureand a knife mounting therefor so worked out that the effective width ofthe knife can be maintained and the amount ground off due to wear can becompensated for.

Another object of the invention is to provide a knife structure and aknife clamp so constructed and arranged that the knife is provided withadjustable means to maintain a uniform effective width, the requiredcompensating adjustment being made prior to securing the knife in theclamp.

Further objects of the invention will appear from the followingspecification taken in connection with the drawing which forms a part ofthis application, and in which Fig. 1 is a fragmentary elevational viewof a portion of the cutter disk illustrating a knife and knife mountingconstructed in accordance with the invention;

Fig. 2 is an enlarged sectional elevation taken substantially on line2-2 of Fig. 1; and

Fig. 3 is a plan view of an end portion of the knife.

In the particular embodiment of the invention illustrated in the drawingthere is shown a chipper disk It! comprising a pair of disk members IIand I2. The disk member 12 is preferably formed of steel and the diskmember H may be formed of cast iron. It should be understood, however,that if desired the disk can be made of a single thickness of material.

The disk I is mounted on a horizontal axis and since the disk mountingforms no part of the present invention further illustration is deemedunnecessary. Attention, however, is directed to applicant's Patent2,247,665, granted July 1, 1941, for an illustration of a chipper diskassembly.

The disk member I2 is provided with an opening l3 and disk member II isprovided with an opening I5 registering with the opening I3. Theseopenings are provided to permit the chips to pass through the disk asthey are cut.

The opening l5 communicates with a larger opening I6 in the disk memberII. The disk member I2 is provided with a recess H in the face of thisdisk member which abuts against the disk member II.

The knife 20 is provided with a beveled front edge 2| and a back edge22. The rear edge portion of the knife has formed therein a plurality ofcurved or arcuate recesses 23 and also a plurality of threaded openings24.

The knife clamp comprises a pair of clamping members 25 and 2B. Theclamping member 25 has a portion 21 adapted to fit in the recess I! inthe disk member I2 and this clamping member has formed therein aplurality of threaded openings 28 which receive bolts 29 by means ofwhich the clamping member 25 is secured to the disk member i2.

The clamping member 25 has formed in its opposite face a V-shaped recess30 having an inclined surface 3| which engages one face of the knife andsupports the knife in position. The V-shaped recessalso has a surface 32substantially at right angles to the surface 3| and engageable by therear or back edge 22 of the knife or by the outer ends of a plurality ofadjustably mounted screws 33 which are threaded into the threadedopenings 24. After the knife has become chipped or worn, it is removedfrom the clamp and re-ground and the screws 33 are then adjusted in theopenings 24 to bring the width of the knife between the beveled end 2|and the rear end of the knife, back to the original width. In otherwords, the effective width of the knife is maintained uniform bycompensating, by means of the screws 33, for the amount ground off ofthe front edge. This is done before the knife is replaced in the clampbetween the clamping members 25 and 26.

The clamping member 26 is triangular in section and has a V-shapedconfiguration adapted to fit against the outer surface of the knife 20and also against the surface 35 of the V-shaped recess 3| in theclamping member 25.

The clamping members 25 and 26 and disk recess or opening I6 thus form apocket for receiving the knife assembly, This pocket is formed betweenthe members 25 and 26, the surface 32 forming the back surface forscrews 22 and forming the back of the pocket. The ends of the pocket areformed by the ends 38 and 39 of the disk opening or recess IS.

The knife assembly and clamping member 26 are secured by means of aplurality of bolts 33, these bolts extending through the disk member l2,clamp member 25, recesses 23 in the knife and being threaded into theclamp member 26.

From the foregoing specification it will be seen that by means of theknife structure and knife mounting described it is possible to maintainthe effective width of the knife uniform even after repeated grinding orre-surfacing of the cutting edge. The efiective width beingpredetermined to permit the knife to project the desired distance width.This adjustment is made prior to the remounting of the knives in theclamp and on the cutting disk.

Although one specific embodiment of the invention has been particularlyshown and described, it will be understood that the invention is capableof modification and that changes in the construction and in thearrangement of the various cooperating parts may be made withoutdeparting from the spirit and scope of the invention, as expressed inthe following claims.

- What I claim is:

1. In combination, a support having a recess therein, a clamp comprisinga pair of members adapted to fit in said recess, said clamp membersforming a pocket for receiving a knife blade, one of the members havinga fiat surface for engaging and supporting one face of the blade and asurface inclined to said flat. surface and forming the back of saidpocket, and a knife blade having means extending rearwardly from theback edge thereof and engageable with said inclined surface, said meansbeing pre-adjustable to an extent to give a predetermined effectivewidth to the knife blade before the knife is inserted in the clamp, theends of the pocket being closed by the ends of the recess in thesupport, whereby the adjusting means will be entirely enclosed in thepocket and inaccessible after the knife has been clamped.

2. In combination a knife support having a pocket extending thereintofrom one face of the support, said pocket having closed ends and havingangularly disposed surfaces arranged to support a knife blade at anangle to the face of the support, one of said surfaces forming a backfor the pocket, a knife blade having a cutting edge at one edge andhaving adjustable means extending rearwardly from the other edge andadapted to be pre-adjusted before the knife blade is inserted in thepocket to give the blade a predetermined effective width, the ends andback of said pocket being closed when the, knife is clamped in place,whereby said adjustable means is inaccessible after the blade has beenclamped in place, said blade resting against one surface of the pocketand said adjustable means abutting the other surface of the pocket whenthe blade is secured therein and means for clamping the blade in thepocket.

3. In combination, a rotatable knife carrier having a pocket extendingthereinto from the face of the carrier, said pocket having closed endsand having a knife supporting surface disposed at an angle to the planeof the path of travel of the knife cutting edge, and having a'knifebacking surface disposed at an "angle to said supporting surface, saidbacking surface forming the back of the pocket, a knife having a cuttingedge at one edge and having adjusting means at the other edge forvarying the effective width of the knife, and means for clamping theknife in the carrier, said clamping means and carrier pocket being soconstructed and arranged that the pocket is closed by the clampingmeans, end of the carrier pocket and backing surface and the adjustingmeans is inaccessible when the knife blade is clamped in place on thecarrier after being pre-adjusted to a predetermined effective width.

4. A chipper knife for use with a support having angularly relatedsurfaces, said knife having a cutting edge at one edge of the knifeblade and having a plurality of adjustable members extending rearwardlyfrom the other edge of the blade and adapted toengage one of saidsurfaces, the second edge having arcuate' notches intermediate saidadjusting members, the axes of the arcs of said notches being disposedat an acute angle to the plane of the knife blade, said notches beingadapted to permit the passage of knife securing bolts.

5. In combination, a knife support having two surfaces disposed inangular relation to each other and approximately at a right angle, aknife having a flat surface adapted to rest on one surface of thesupport and having adjustable means at the rear edge adapted to seatagainst the other surface, a clamping member for clamping the knifeblade against said supporting surfaces and bolts for securing theclamping member, the rear edge of the blade being grooved at an acuteangle to the plane of the knife blade to permit passage of the bolts.

PETER N. OT'IERSLAND.

